The present application relates to a swiveling electrical connector. More specifically, the present application describes an electrical connector having two assemblies which freely rotate relative to each other and which may be quickly connected and disconnected.
The use of electrical power tools on building construction sites necessitates the reliable distribution of high-current electrical power throughout the often chaotic and obstacle-laden environment which such sites represent. Typically, power is distributed on such sites through the use of conventional electrical extension cords which are terminated with fixed, three-prong plugs and receptacles. As is well known to construction workers, such fixed connectors present a variety of practical problems. For example, the nature of construction work is such that the worker often must move over a considerable area and maneuver himself in close quarters while using the same power tool. Under such conditions, fixed connectors tend to twist and knot creating hazardous conditions as well as causing considerable wear and tear on the respective power cords. Moreover, as fixed connectors are dragged through the construction site, they tend to snag on comers and other obstacles resulting in disconnection due to the tension on the power cord which, in turn, results in a reduction in the efficiency of the worker as he scrambles to reconnect the line or free up a snag. To prevent such disconnections, workers typically knot the cords together near the connection. However, this merely tends to exacerbate the problems related to cord wear and snagging.
Other problems relate to the fact that construction workers typically use a variety of different power tools in a single work area. In general, power tools have power cords built into their handles which are several feet long and which are terminated with fixed three-prong plugs. When switching power tools, the worker must reach the connection, disconnect the current power tool, connect the new power tool, and store the disconnected power tool. If the worker is in a precarious position such an operation is difficult at best. That is, the connection may be several feet away and out of reach unless the worker extricates himself from his working position. In addition, the built in cords of the power tools present handling and storage problems which are often difficult to deal with under practical conditions.
Attempts have been made to address some of the problems discussed above with swiveling electrical connectors. However, none of these connectors provides features which address all of these problems. For example, U.S. Pat. No. 1,174,379, No. 2,176,137, No. 2,181,145, No. 2,465,022, No. 2,474,070, No. 3,387,250, and No. 4,894,014 all describe various electrical connectors each of which has two assemblies which rotate relative to each other. However, none of these designs is appropriate for use in the construction environment in that they provide for connection between electrical cords having only two conductors. Because of the additional complexity represented by a third conductor, none of the designs described in these patent could be readily converted to provide a rotatable connection for three conductors. Moreover, all of these connectors maintain permanent connections between the two assemblies. While this may prevent disconnection problems, it fails to address the problems discussed above with regard to the interchangeability of power tools.
The rotatable connector described by U.S. Pat. No. 3,321,729 has two permanently connected assemblies 12 and 50 which rotate relative to each other. While this design allows connection and disconnection from separate power cords via prongs 38, 40 and receptacles 64, 66, it does not address the problem of cord disconnection due to tension. In addition, the power cords connected by this device have only two conductors.
U.S. Pat. No. 3,629,784 describes a three-conductor swivel connection which is permanently fixed in the handle of a power tool. While this design may alleviate some of the problems related to the twisting and knotting of power tool power cords, it does not address the problems associated with the need to quickly and efficiently switch between power tools. Moreover, because a connection must still be made between the other end of the tool's power cord and an extension cord (presumably using the conventional three-prong plug and receptacle), all of the hazards associated with such a connection are still present.
From the foregoing, it is apparent that there is a need for a swiveling electrical connector which provides a connection between power cords having three conductors, maintains the connection even under considerable tension, and is quickly and easily connected and disconnected.